'75 280z can't get spark

[tamo3]

I know there are a lot of "Can't get spark" topic before here and there.

I read through those topics but still can' figure out what was wrong with my case.

It was running strong before I shut off engine.

 

Next day, I cannot start engine.

Trouble shooting what I have done follow 280zfuelinjectionbook.pdf

Fuel pump

1. Remove Starter motor IGN line.
2. Turn key on to the IGN position to hear fuel pump sound. It works.

 

Spark check

1. Remove Spark Plug and leave it on the top of valve cover with cable connect
2. Trun key onto the IGN position.
3. No spark!

 

IGN signal blue line check

1. Under the dashboard, Check blue line is connected.

 

 

Coil Check

1. Use voltmeter set to 20
2. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Battery Negative post. Result show 12V. Passed
3. Connect Voltmeter Positive to Battery Positive post and Voltmeter Negative to Coil Negative. Result show 12V. Passed.
4. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Coil Negative. Turn key onto IGN position. Result 0V. FAILED

What should I test next?

Edited October 2, 2017 by tamo3

[Zed Head]

57 minutes ago, tamo3 said:

1. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Coil Negative. Turn key onto IGN position. Result 0V. FAILED

What should I test next?

This part would be normal.. The + and the - have the same voltage if no current is flowing.

The two things most likely to be the source of the problem are the ignition module and the pickup coils in the distributor.  The pickup coils are pretty easy, check resistance, and air gap.  The ignition module is a little bit harder.

Might also be that something broke inside the distributor.  When you check air gap, you'll see if that's the case.

[EuroDat]

Tamo, You have the Californian model right?

The FED system has a cold start system to retard and advance the timing by changing pickups in the distributor. You can see then with the distributor cap off, or the three wires (green, brown & red), and the 7 wire TIU. The pickups are not 180 degrees apart, but I can not remember exactly how many degrees they are.

No real way to test the module with a multi meter, except check it is getting voltage. Basically go through a process of elimination until it's the only thing left.

If you look in the last section of the instruction there is some trouble shooting steps you can take. It's written for the HEI swap, but the original should work the same.

 

TIU280Z1976_REV1.pdf

Instruction - Fitting a 4-pin HEI module to 280Z 1977 RevD.pdf

[tamo3]

Thanks Zed Head, Chas for your input.

My 280z is none CA model. 

Actually, after this problem, I thought ignition module or dizzy itself failure.

So, i decided to swap to 280zx distributor.

I follows blues instruction. http://atlanticz.ca/zclub/techtips/distributor/index.html

I need to modify one line. BL line needs to added to positive post on Coil. Otherwise, nothing happen when I turn key onto IGN position.

 

 

Now I can get rid of those...

 

Even though after swapping Dizzy, and get rid of ignition module, the symptom hasn't been changed.

 

 

[Zed Head]

1 hour ago, tamo3 said:

, the symptom hasn't been changed.

No start, or no spark and no start?  With the new distributor you should certainly get spark.  Unless it's not turning.  People have had the distributor drive shaft gear slip.  You might remove the distributor cap and make sure that the rotor is spinning.  (Also make sure that you installed a rotor on the new distributor.  People have forgotten.).

[tamo3]

I installed new rotor and new cap too.

 

Spinning rotor check

 

[tamo3]

Here is spark test.

 

[EuroDat]

I can't watch the videos atm because they chew up my data on a pre-paid sim while Im in Australia. My work phone has unlimited data, but Im too far away from that providers mask.

Are you grounding the spark plug correctly when doing the test?

When I read your post about checking voltage. You say 12V. Is that exactly the same as battery voltage? A small voltage drop can mean a lot if you have no current draw.

Can you check the coil by attaching a wire to the negative post and and quickly tapping the wire to ground while the ignition is on. You will need to connect a spark plug to the HT lead coming from the coil to the dissy cap.

If you don't get any kind of spark, you have a faulty coil or the power supply going to it.

[Zed Head]

2 hours ago, EuroDat said:

Are you grounding the spark plug correctly when doing the test?

EuroChas might have uncovered one problem with test method.  The electrode is not grounded in the spark test video.  Any part of the metal body of the plug needs to be touching a ground point.  The valve cover usually woks well.

If you re-run the test and find that you have spark that will narrow things down.  You could also put everything back together and try starting fluid.  If it starts for a few seconds then you'll know you have a fuel issue.

[tamo3]

Thanks Chas, Zed Head. I put spark plug onto the valve cover to test it again.

The result was same

 

 

Coil test: Positive Post

1. Connect Voltmeter Positive to Coil Positive and Voltmeter Negative to Battery Negative post. Default shows 0v. When turn IGN, it show 12V. 

 

Coil test: Negative Post

Connect Voltmeter Negative to Coil Negative and Voltmeter Positive to Battery Positive post. Default shows 12v. When turn IGN, it dropped to 0.31v. 

 

 

[Zed Head]

I would use the center wire from the coil, as Chas mentioned, not a spark plug wire.  You can stick a bolt in it or maybe a spark plug.  Then you'll get six times as many sparks, if the coil and ignition module are okay. 

If you still don't get any spark, connect a small wire to the coil's negative post (Chas's suggestion again), turn the key on, and tap the other end of the wire to ground.  Have the center wire of the coil, with something metallic in it, close to ground, about a spark plug gap away.  You should see a small spark there and a big spark from the end of the center wire of the coil.  You will be essentially acting as the ignition module, making and breaking the coil power circuit.  This test will narrow it all down to the coil.  As Chas said, if you don't get a spark with this test your coil is bad.

When you did the test below, what you did was connect the two leads to essentially the same point.  The coil negative is connected to the battery positive post, through the coil, then the positive post and the wiring.  Every thing looks about right on your measurements.  Do the test with the wire on the negative post.  Connect the wire, let it hang in space, turn on the key, tap-spark-tap-spark-tap...is what should happen.  Your injectors should click on every third tap also.  It's a simple test of the ECU and wiring, in addition to the coil

2 hours ago, tamo3 said:

Coil test: Negative Post

Connect Voltmeter Negative to Coil Negative and Voltmeter Positive to Battery Positive post. Default shows 12v. When turn IGN, it dropped to 0.31v. 

 

[tamo3]

Looks like it's coil failure.

This MSD Blaster 2 is not so old... ;-(. I will order new one.